The purpose of this study was to explore the relationship between principals' self-efficacy beliefs and stress and the relationship with schools' and principals' attributes. The sample of the study consisted of (182) principals chosen randomly from three regions in Oman: Batnah North, Batnah South and Muscat. The data were collected by using two instruments, the Principals Self Efficacy Scale (PSES, Tschannen-Moran & Garies, 2004) and the stress scale (Al-Rawas, 2003). The findings of the study can be summarized as follows: - The Omani principals had high levels of self-efficacy beliefs and moderated levels of stress. There were no significant differences between males and females in self-efficacy beliefs. There were no significant differences in self-efficacy beliefs due to the total of the students. - There were no significant correlations in self-efficacy beliefs due to the experience of the principal. - There were no significant correlations between self-efficacy beliefs and the total number of students. - There was a negative significant correlation between Omani principal's self-efficacy beliefs and stress. - The results of the study were discussed with some recommendations and suggestions for further researches